WHSC2 Human
Description
Functional Roles
Transcriptional Regulation
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WHSC2/NELFA is a core subunit of the NELF complex, which collaborates with the DRB sensitivity-inducing factor (DSIF) to pause RNA Pol II during transcription elongation . This pausing synchronizes transcriptional bursts, particularly during rapid developmental processes .
Developmental Contributions
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Neural Crest Development: WHSC2 depletion disrupts craniofacial cartilage formation and neural crest cell motility, contributing to WHS-associated facial dysmorphisms (e.g., "Greek Warrior Helmet" phenotype) .
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Cell Cycle and Chromatin Dynamics: Haploinsufficiency of WHSC2 correlates with delayed S-phase progression, altered histone-chromatin association, and increased DNA replication stress .
Disease Associations
Clinical and Research Insights
Wolf-Hirschhorn Syndrome (WHS)
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WHSC2 resides within the 165 kb WHS critical region . While WHS is primarily attributed to WHSC1 deletions, WHSC2 haploinsufficiency exacerbates craniofacial defects and neural crest migration deficits .
Recombinant WHSC2 Tools
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Applications: Used to study transcriptional pausing, chromatin dynamics, and WHS pathophysiology .
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Commercial Variants:
Key Research Findings
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Neural Crest Defects: WHSC2 depletion in Xenopus models reduces cranial cartilage volume by 30% and disrupts neural crest migration .
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Cancer Relevance: WHSC2-derived peptides are recognized by HLA-A2-restricted T cells, suggesting utility in cancer immunotherapy .
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Chromatin Phenotypes: Cells from WHS patients show 40% reduced histone H3-chromatin binding and increased sensitivity to DNA-damaging agents .
Unresolved Questions
Product Specs
MGSSHHHHHH SSGLVPRGSH MPGQRRALSP KMASMRESDT GLWLHNKLGA TDELWAPPSI ASLLTAAVID NIRLCFHGLS SAVKLKLLLG TLHLPRRTVD EMKGALMEII QLASLDSDPW VLMVADILKS FPDTGSLNLE LEEQNPNVQD ILGELREKVG ECEASAMLPL ECQYLNKNAL TTLAGPLTPP VKHFQLKRKP KSATLRAELL QKSTETAQQL KRSAGVPFHA KGRGLLRKMD TTTPLKGIPK QAPFRSPTAP SVFSPTGNRT PIPPSRTLLR KERGVKLLDI SELDMVGAGR EAKRRRKTLD AEVVEKPAKE ETVVENATPD YAAGLVSTQK LGSLNNEPAL PSTSYLPSTP SVVPASSYIP SSETPPAPSS REASRPPEEP SAPSPTLPAQ FKQRAPMYNS GLSPATPTPA APTSPLTPTT PPAVAPTTQT PPVAMVAPQT QAPAQQQPKK NLSLTREQMF AAQEMFKTAN KVTRPEKALI LGFMAGSREN PCQEQGDVIQ IKLSEHTEDL PKADGQGSTT MLVDTVFEMN YATGQWTRFK KYKPMTNVS.
Q&A
What is WHSC2 and what is its role in human cellular function?
WHSC2, also known as NELF-A, is a gene mapped to the 165 kb Wolf-Hirschhorn syndrome (WHS) critical region on chromosome 4p16.3. It encodes a protein component of the NELF complex that functions to decelerate or pause RNA polymerase II activity during transcription elongation . This pausing mechanism is thought to function as a means of synchronizing rapid or constitutive expression of specific transcripts . WHSC2 is expressed ubiquitously throughout human tissues, with notably higher expression levels in fetal tissues compared to adult tissues, indicating its developmental importance .
The WHSC2 protein shares approximately 93% sequence identity with its mouse homolog, suggesting high evolutionary conservation and fundamental importance in cellular function . The protein has been shown to be a member of the NELF complex that participates in the regulation of RNA polymerase II transcription elongation, providing a critical checkpoint in gene expression control .
How is WHSC2 associated with Wolf-Hirschhorn syndrome?
Wolf-Hirschhorn syndrome (WHS) is a contiguous gene deletion disorder associated with the distal part of the short arm of chromosome 4 (4p16.3). Approximately 55% of cases are due to de novo terminal deletions . Two Wolf-Hirschhorn critical regions, WHSCR1 and WHSCR2, have been identified within 4p16.3, with WHSCR2 being distal to and overlapping with WHSCR1 .
Research using patient-derived cell lines with differing-sized 4p deletions has provided evidence that haploinsufficiency of WHSC2 contributes to several novel cellular phenotypes characteristic of WHS . This gene is mapped to the 165 kb WHS critical region and may play a role in the phenotype of WHS or Pitt-Rogers-Danks syndrome . The cellular abnormalities resulting from WHSC2 deficiency likely underlie or contribute to the core clinical features of WHS, including microcephaly and pre- and postnatal growth retardation .
What cellular phenotypes are associated with WHSC2 haploinsufficiency?
Studies using patient-derived cell lines have revealed several cellular phenotypes associated with WHSC2 haploinsufficiency:
These cellular abnormalities provide novel pathogenomic insight into the aetiology of WHS by characterizing it as a disorder of impaired chromatin reorganization . The delayed cell-cycle progression and impaired DNA replication likely contribute to the microcephaly and growth retardation that are core clinical features of the syndrome .
What techniques are commonly used to study WHSC2 expression and function?
Researchers employ various techniques to investigate WHSC2 expression and function:
For overexpression studies, recombinant AAV vectors expressing human WHSC2/NELFA are available with various promoter options (including CMV) and in multiple AAV serotypes (AAV1, AAV2, AAV3, AAV5, AAV6, AAV8, AAV9, AAV-DJ, and others) .
How does WHSC2/NELF-A influence RNA polymerase II activity and what are the implications for gene expression?
WHSC2/NELF-A functions within the NELF complex to decelerate or pause RNA polymerase II activity during transcription elongation . This pausing mechanism is not merely inhibitory but represents a sophisticated regulatory mechanism that serves to synchronize rapid or constitutive expression of specific transcripts . The NELF complex components, including WHSC2, are required during early embryogenesis, highlighting their developmental importance .
The pausing mechanism regulated by the NELF complex is thought to function as a means of coordinating gene expression, particularly for genes that require precise temporal control . This is especially critical during development when coordinated expression of multiple genes is essential for proper morphogenesis. Dysregulation of this process due to WHSC2 haploinsufficiency likely contributes to the developmental abnormalities observed in WHS patients.
Recent research suggests the NELF complex facilitates cancer cell proliferation and motility, downstream of its regulation of cell-cycle control transcripts . This indicates that WHSC2's role extends beyond basic transcriptional regulation to influence complex cellular behaviors, potentially explaining some of the pleiotropic effects of its deficiency.
What is the relationship between WHSC2 and chromatin reorganization in Wolf-Hirschhorn syndrome?
Research on WHS patient-derived cell lines has revealed that haploinsufficiency of WHSC2 contributes to altered higher order chromatin assembly . This represents a novel pathogenomic insight into the aetiology of WHS, describing it for the first time as a disorder of impaired chromatin reorganization .
The evidence for this relationship includes:
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Reduced histone–chromatin association in WHS patient cells
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Elevated levels of soluble chaperone-bound histone H3
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Increased sensitivity to micrococcal nuclease digestion in WHS patient-derived cells
These findings suggest that WHSC2 plays a crucial role in maintaining proper chromatin structure, which is essential for normal gene expression and cellular function. The chromatin reorganization defects observed in WHS cells likely contribute to the global dysregulation of gene expression that underlies the diverse clinical manifestations of the syndrome.
How does WHSC2 function in neural crest development and craniofacial morphogenesis?
Research has demonstrated consistent enrichment of WHS-associated genes, including WHSC2, in cranial neural crest (CNC) cells . Several WHS-associated genes significantly impact facial patterning, cartilage formation, and neural crest motility both in vivo and in vitro . The involvement of WHSC2 in neural crest development provides a mechanistic link to the characteristic facial phenotypes observed in WHS patients.
The NELF complex, of which WHSC2/NELF-A is a component, may be particularly important in CNC development due to the unique requirements of these cells to undergo both rapid proliferation and directed migration during morphogenesis . Given that motility and proliferation inherently compete for cytoskeletal machinery, the CNC's need to undergo both rapid expansion and directed motility within the same developmental stages may benefit from the additional levels of coordination provided by the NELF complex .
This hypothesis remains speculative, but the consistent enrichment of WHS-associated genes in CNCs, and their necessity for normal formation of their derivatives, suggests a critical role for WHSC2 in craniofacial development that warrants further investigation .
How might WHSC2's function in cell cycle regulation contribute to WHS clinical manifestations?
WHSC2 haploinsufficiency leads to delayed progression from S-phase into M-phase and reduced DNA replication in asynchronous culture . These cell cycle defects likely contribute to key clinical features of WHS, particularly microcephaly and pre- and postnatal growth retardation, which constitute the core clinical features of the syndrome .
Additionally, the role of the NELF complex in facilitating both cell proliferation and motility suggests that WHSC2 deficiency could disrupt the coordinated balance between these processes during development. This may be especially detrimental in tissues where precise temporal and spatial control of cell proliferation and movement is essential, such as during neuronal migration in brain development.
What potential role does WHSC2 play in cancer biology and therapeutic development?
The WHSC2-encoded protein is found to be capable of reacting with HLA-A2-restricted and tumor-specific cytotoxic T lymphocytes, suggesting potential as a target for specific immunotherapy for a large number of cancer patients . This immunological property makes WHSC2 of interest in the development of cancer immunotherapies.
Recent work suggests the NELF complex facilitates cancer cell proliferation and motility, downstream of its regulation of cell-cycle control transcripts . Given that motility and proliferation inherently compete for cytoskeletal machinery, the coordinating function of the NELF complex may be particularly relevant to cancer metastasis, where cells must both proliferate and migrate.
The potential dual role of WHSC2 in cancer biology – both as an immunotherapeutic target and as a regulator of cancer cell behavior – makes it an intriguing subject for cancer research. Further investigation into how WHSC2 influences tumor cell proliferation, invasion, and interaction with the immune system could lead to novel therapeutic approaches.
Product Science Overview
Wolf-Hirschhorn Syndrome (WHS) is a multiple malformation syndrome characterized by mental and developmental defects. It results from a hemizygous deletion of the distal short arm of chromosome 4 (4p16.3) . The syndrome is named after the German geneticists Kurt Hirschhorn and Ulrich Wolf, who first described it in the 1960s. Individuals with WHS often exhibit distinctive facial features, growth delays, intellectual disabilities, and seizures.
The WHSC2 protein is encoded by the WHSC2 gene, which is located on the short arm of chromosome 4. The recombinant form of this protein, referred to as WHSC2 Human Recombinant, is produced in Escherichia coli (E. coli) and is fused with a 20 amino acid His-tag at the N-terminus . This recombinant protein is a single, non-glycosylated polypeptide chain containing 559 amino acids and has a molecular mass of approximately 60.6 kDa .
The production of WHSC2 Human Recombinant involves the expression of the WHSC2 gene in E. coli. The protein is then purified using proprietary chromatographic techniques to achieve a purity greater than 85% as determined by SDS-PAGE . The protein is formulated in a buffer containing 20 mM Tris-HCl (pH 8.0), 0.2 M NaCl, 5 mM DTT, 1 mM EDTA, and 20% glycerol .
WHSC2 Human Recombinant is used in various research and development applications, particularly in studies related to transcription regulation and the molecular mechanisms underlying Wolf-Hirschhorn Syndrome. The protein’s role in repressing RNA polymerase II elongation makes it a valuable tool for understanding the regulation of gene expression .
